477 Works

Aerodynamics of Vertical-axis Wind Turbines in Full-scale and Laboratory-scale Experiments

Daniel Borsodi Araya
Within a wind farm, multiple turbine wakes can interact and have a substantial effect on the overall power production. This makes an understanding of the wake recovery process critically important to optimizing wind farm efficiency. Vertical-axis wind turbines (VAWTs) exhibit features that are amenable to dramatically improving this efficiency. However, the physics of the flow around VAWTs is not well understood, especially as it pertains to wake interactions, and it is the goal of this...

I. Quantal effects in biochemical cooperativity and a proposed mechanism for the differentiation of calcium signaling in synaptic plasticity. II. Evolutionary algorithms for the optimization of methods in computational chemistry

William Chastang Ford
In Part 1 of this thesis, we propose that biochemical cooperativity is a fundamentally non-ideal process. We show quantal effects underlying biochemical cooperativity and highlight apparent ergodic breaking at small volumes. The apparent ergodic breaking manifests itself in a divergence of deterministic and stochastic models. We further predict that this divergence of deterministic and stochastic results is a failure of the deterministic methods rather than an issue of stochastic simulations. Ergodic breaking at small volumes...

Chemical Reaction Dynamics of the Liquid/Vapor Interface Studied by Mass Spectrometry

Daniel Aaron Thomas
This thesis presents investigations of chemical reactions occurring at the liquid/vapor interface studied using novel sampling methodologies coupled with detection by mass spectrometry. Chapters 2 and 3 utilize the recently developed technique of field-induced droplet ionization mass spectrometry (FIDI-MS), in which the application of a strong electric field to a pendant microliter droplet results in the ejection of highly charged progeny droplets from the liquid surface. In Chapter 2, this method is employed to study...

Band Engineering in Thermoelectric Materials Using Optical, Electronic, and Ab-Initio Computed Properties

Zachary Michael Gibbs
Thermoelectric materials have demanded a significant amount of attention for their ability to convert waste heat directly to electricity with no moving parts. A resurgence in thermoelectrics research has led to significant enhancements in the thermoelectric figure of merit, zT, even for materials that were already well studied. This thesis approaches thermoelectric zT optimization by developing a detailed understanding of the electronic structure using a combination of electronic/thermoelectric properties, optical properties, and ab-initio computed electronic...

DNA-Mediated Charge Transport Signaling Within the Cell

Michael Andrew Grodick
DNA possesses the curious ability to conduct charge longitudinally through the π-stacked base pairs that reside within the interior of the double helix. The rate of charge transport (CT) through DNA has a shallow distance dependence. DNA CT can occur over at least 34 nm, a very long molecular distance. Lastly, DNA CT is exquisitely sensitive to disruptions, such as DNA damage, that affect the dynamics of base-pair stacking. Many DNA repair and DNA-processing enzymes...

Self-assembly of Brush Polymers

Benjamín Ragnar Sveinbjörnsson
The unique structure and properties of brush polymers have led to increased interest in them within the scientific community. This thesis describes studies on the self-assembly of these brush polymers. Chapter 2 describes a study on the rapid self-assembly of brush block copolymers into nanostructures with photonic bandgaps spanning the entire visible spectrum, from ultraviolet to near infrared. Linear relationships are observed between the peak wavelengths of reflection and polymer molecular weights. This work enables...

Organic Matter Sulfurization in the Modern Ocean

Morgan Reed Raven
Only a tiny fraction of the carbon fixed by primary producers in the surface ocean is preserved in sediments, but this organic matter (OM) burial is one of the main processes linking the short and long-term carbon cycles, giving it important roles in global biogeochemistry. OM-rich deposits often contain abundant organic S (OS), and sulfur incorporation is thought to make OM less available for heterotrophs and more likely to be preserved. Still, we have few...

Zn-VI/Cu2O Heterojunctions for Earth-Abundant Photovoltaics

Samantha Stricklin Wilson
The need for sustainable energy production motivates the study of photovoltaic materials, which convert energy from sunlight directly into electricity. This work has focused on the development of Cu2O as an earth-abundant solar absorber due to the abundance of its constituent elements in the earth's crust, its suitable band gap, and its potential for low cost processing. Crystalline wafers of Cu2O with minority carrier diffusion lengths on the order of microns can be manufactured in...

Quantifying Earthquake Collapse Risk of Tall Steel Braced Frame Buildings Using Rupture-to-Rafters Simulations

Ramses Mourhatch
This thesis examines collapse risk of tall steel braced frame buildings using rupture-to-rafters simulations due to suite of San Andreas earthquakes. Two key advancements in this work are the development of (i) a rational methodology for assigning scenario earthquake probabilities and (ii) an artificial correction-free approach to broadband ground motion simulation. The work can be divided into the following sections: earthquake source modeling, earthquake probability calculations, ground motion simulations, building response, and performance analysis. As...

Robust Control of Evolutionary Dynamics

Vanessa Danielle Jonsson
The application of principles from evolutionary biology has long been used to gain new insights into the progression and clinical control of both infectious diseases and neoplasms. This iterative evolutionary process consists of expansion, diversification and selection within an adaptive landscape - species are subject to random genetic or epigenetic alterations that result in variations; genetic information is inherited through asexual reproduction and strong selective pressures such as therapeutic intervention can lead to the adaptation...

Dynamic Characterization of Micro-Particle Systems

Wei-Hsun Lin
Ordered granular systems have been a subject of active research for decades. Due to their rich dynamic response and nonlinearity, ordered granular systems have been suggested for several applications, such as solitary wave focusing, acoustic signals manipulation, and vibration absorption. Most of the fundamental research performed on ordered granular systems has focused on macro-scale examples. However, most engineering applications require these systems to operate at much smaller scales. Very little is known about the response...

Optical Phase Conjugation and Its Applications in Biology

Mooseok Jang
Optical phase conjugation is a process where an incoming electromagnetic wave is reflected with a reversed phase. The propagation direction of an incoming beam (equivalently, local phase gradient) can thereby be precisely reversed by the phase conjugate beam. This intriguing effect, so called "time-reversal of electromagnetic waves," allows cancellation of spatial distortion introduced into the incoming beam. Recently, this concept has provided a new avenue to overcome or utilize random scattering in the field of...

Physical, Metabolic, and Energetic Investigations of Methane-Metabolizing Microbial Communities

Jeffrey James Marlow
Understanding the roles of microorganisms in environmental settings by linking phylogenetic identity to metabolic function is a key challenge in delineating their broad-scale impact and functional diversity throughout the biosphere. This work addresses and extends such questions in the context of marine methane seeps, which represent globally relevant conduits for an important greenhouse gas. Through the application and development of a range of culture-independent tools, novel habitats for methanotrophic microbial communities were identified, established settings...

Development of Zn-IV-Nitride Semiconductor Materials and Devices

Amanda M. Shing
This thesis details explorations of the materials and device fabrication of Zn-IV-Nitride thin-films. Motivation in studying this materials series originates from its analgous properties to the III-Nitride semiconductor materials and its potential applications in photonic devices such as solar cells, light emitting diodes, and optical sensors. Building off of initial fabrication work from Coronel, Lahourcade et al., ZnSnxGe1-xN2 thin-films have shown to be a non-phase-segregating, tunable alloy series and a possible earth-abundant alternative to InxGa1-xN...

Reconstructing Past Depositional and Diagenetic Processes through Quantitative Stratigraphic Analysis of the Martian Sedimentary Rock Record

Kathryn Marie Morgan Stack
High-resolution orbital and in situ observations acquired of the Martian surface during the past two decades provide the opportunity to study the rock record of Mars at an unprecedented level of detail. This dissertation consists of four studies whose common goal is to establish new standards for the quantitative analysis of visible and near-infrared data from the surface of Mars. Through the compilation of global image inventories, application of stratigraphic and sedimentologic statistical methods, and...

Synthetic Circuits for Feedback and Detection in Bacteria

Victoria Hsiao
Synthetic biology, by co-opting molecular machinery from existing organisms, can be used as a tool for building new genetic systems from scratch, for understanding natural networks through perturbation, or for hybrid circuits that piggy-back on existing cellular infrastructure. Although the toolbox for genetic circuits has greatly expanded in recent years, it is still difficult to separate the circuit function from its specific molecular implementation. In this thesis, we discuss the function-driven design of two synthetic...

Imidazolium-Based Organic Structure Directing Agents for the Synthesis of Microporous Materials

Joel Edward Schmidt
The central theme of this thesis is the use of imidazolium-based organic structure directing agents (OSDAs) in microporous materials synthesis. Imidazoliums are advantageous OSDAs as they are relatively inexpensive and simple to prepare, show robust stability under microporous material synthesis conditions, have led to a wide range of products, and have many permutations in structure that can be explored. The work I present involves the use of mono-, di-, and triquaternary imidazolium-based OSDAs in a...

The Catalytic and Mechanical Properties of Lithium Battery Electrodes

Chen Xu
The mass adoption of electric vehicles warrants higher energy densities at lower costs. Novel chemistries such as Li-S or Li-air, high energy density anodes such as lithium (Li) metal are some of the ways to address the aforementioned issue. However, many scientific challenges must be overcome in order to achieve the successful commercialization of these batteries. For Li-air, poor cyclability and low coulumbic efficiency are key obstacles. The search for cathode materials that exhibit high...

Binding Site Structure and Stoichiometry in Serotonin Type 3 Receptors

Timothy Francis Miles
This dissertation primarily describes studies of serotonin type 3 (5-HT3) receptors of the Cys-loop super-family of ligand gated ion channels. The first chapter provides a general introduction to these important proteins and the methods used to interrogate their structure and function. The second chapter details the delineation of a structural unit of the ligand binding site of homomeric 5-HT3A receptors on which the ligands serotonin (5-HT) and m-chlorophenyl biguanide (mCPBG) are reliant for effective receptor...

Software Design System

Computer Science Technical Reports

Scalable Methods for Deterministic Integration of Quantum Emitters in Photonic Crystal Cavities

Andrew P. Homyk
We investigated four unique methods for achieving scalable, deterministic integration of quantum emitters into ultra-high Q{V photonic crystal cavities, including selective area heteroepitaxy, engineered photoemission from silicon nanostructures, wafer bonding and dimensional reduction of III-V quantum wells, and cavity-enhanced optical trapping. In these areas, we were able to demonstrate site-selective heteroepitaxy, size-tunable photoluminescence from silicon nanostructures, Purcell modification of QW emission spectra, and limits of cavity-enhanced optical trapping designs which exceed any reports in the...

New insights into the formation and modification of carbonate-bearing minerals and methane gas in geological systems using multiply substituted isotopologues

Daniel Aaron Stolper
This thesis describes the use of multiply-substituted stable isotopologues of carbonate minerals and methane gas to better understand how these environmentally significant minerals and gases form and are modified throughout their geological histories. Stable isotopes have a long tradition in earth science as a tool for providing quantitative constraints on how molecules, in or on the earth, formed in both the present and past. Nearly all studies, until recently, have only measured the bulk concentrations...

Registration Year

  • 2016
    477

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